ESP32 SHT20驱动代码 ESP-IDF+VScode

本工程使用ESP-IDF5.0+VScode编程。

代码基于官方simple_i2c例程修改。

main函数内容。

#include <stdio.h>
#include "esp_log.h"
#include "driver/i2c.h"
#include "./../Include/SHT20.h"

static const char *TAG = "i2c-simple-example";

void app_main(void)
{

    ESP_ERROR_CHECK(i2c_master_init());
    ESP_LOGI(TAG, "I2C initialized successfully");

    while (1)
    {
        printf("Tempreture = %.2f℃\n", SHT20_Get_Tempreture());
        printf("Humidity = %.2f%%\n\n", SHT20_Get_Humidity());
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

SHT20.c文件内容

#include <stdio.h>
#include "driver/i2c.h"
#include "esp_log.h"
#include "./../Include/SHT20.h"

esp_err_t i2c_master_init(void)
{
    int i2c_master_port = I2C_MASTER_NUM;

    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_MASTER_FREQ_HZ,
    };

    i2c_param_config(i2c_master_port, &conf);

    return i2c_driver_install(i2c_master_port, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
}
// 非占用总线的温度测量，默认14bit数据。
float SHT20_Get_Tempreture(void)
{
    uint8_t data[2] = {0, 0};
    float Tempreture = 0;
    i2c_cmd_handle_t handle = i2c_cmd_link_create();

    i2c_master_start(handle);
    i2c_master_write_byte(handle, SHT20_SENSOR_ADDR << 1 | 0, ACK_CHECK_EN);
    i2c_master_write_byte(handle, SHT20_SENSOR_TMEASUREMENT_NOHOLD_ADDR, ACK_CHECK_EN);
    vTaskDelay(0.02 / portTICK_PERIOD_MS);
    i2c_master_stop(handle);

    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);
    vTaskDelay(90 / portTICK_PERIOD_MS);

    handle = i2c_cmd_link_create();
    i2c_master_start(handle);
    i2c_master_write_byte(handle, SHT20_SENSOR_ADDR << 1 | 1, ACK_CHECK_EN);
    i2c_master_read_byte(handle, &data[0], ACK_VAL);
    i2c_master_read_byte(handle, &data[1], NACK_VAL);
    // i2c_master_read_byte(handle,&data[2],NACK_VAL);抛弃校验和，想要校验和，上一行改为ACK_VAL，取消注释此行
    i2c_master_stop(handle);

    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);

    Tempreture = (data[0] << 8) | (data[1] & 0xFC);
    Tempreture = 175.72 * ((float)Tempreture / 65536) - 46.85;
    return Tempreture;
}
// 非占用总线的湿度测量，默认12bit数据。
float SHT20_Get_Humidity(void)
{
    uint8_t data[2] = {0, 0};
    float Humidity = 0;
    i2c_cmd_handle_t handle = i2c_cmd_link_create();

    i2c_master_start(handle);
    i2c_master_write_byte(handle, SHT20_SENSOR_ADDR << 1 | 0, ACK_CHECK_EN);
    i2c_master_write_byte(handle, SHT20_SENSOR_RHMEASUREMENT_NOHOLD_ADDR, ACK_CHECK_EN);
    vTaskDelay(0.02 / portTICK_PERIOD_MS);
    i2c_master_stop(handle);

    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);
    vTaskDelay(35 / portTICK_PERIOD_MS);

    handle = i2c_cmd_link_create();
    i2c_master_start(handle);
    i2c_master_write_byte(handle, SHT20_SENSOR_ADDR << 1 | 1, ACK_CHECK_EN);
    i2c_master_read_byte(handle, &data[0], ACK_VAL);
    i2c_master_read_byte(handle, &data[1], NACK_VAL);
    // i2c_master_read_byte(handle,&data[2],NACK_VAL);抛弃校验和，想要校验和，上一行改为ACK_VAL，取消注释此行
    i2c_master_stop(handle);

    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);

    Humidity = (data[0] << 8) | (data[1] & 0xFC);
    Humidity = 125 * ((float)Humidity / 65536) - 6;
    return Humidity;
}

SHT20.h文件内容

#ifndef _SHT20_H_
#define _SHT20_H_

#define I2C_MASTER_SCL_IO 4         /*!< GPIO number used for I2C master clock */
#define I2C_MASTER_SDA_IO 15        /*!< GPIO number used for I2C master data  */
#define I2C_MASTER_NUM 1            /*!< I2C master i2c port number, the number of i2c peripheral interfaces available will depend on the chip */
#define I2C_MASTER_FREQ_HZ 400000   /*!< I2C master clock frequency */
#define I2C_MASTER_TX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define I2C_MASTER_RX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define I2C_MASTER_TIMEOUT_MS 1000

#define ACK_CHECK_EN 0x1  /*!< I2C master will check ack from slave*/
#define ACK_CHECK_DIS 0x0 /*!< I2C master will not check ack from slave */
#define ACK_VAL 0x0       /*!< I2C ack value */
#define NACK_VAL 0x1      /*!< I2C nack value */

#define SHT20_SENSOR_ADDR 0x40                      /*!< Slave address of the SHT20 sensor */
#define SHT20_SENSOR_TMEASUREMENT_NOHOLD_ADDR 0xF3  /*!< Register addresses of the "who am I" register */
#define SHT20_SENSOR_RHMEASUREMENT_NOHOLD_ADDR 0xF5 /*!< Register addresses of the "who am I" register */
// #define SHT20_SENSOR_USER_REG_ADDR 0xE7             /*!< Register addresses of the "who am I" register */

esp_err_t i2c_master_init(void);
float SHT20_Get_Tempreture(void);
float SHT20_Get_Humidity(void);
#endif /*_SHT20_H_*/